Mailing List Archive

commit 3a669ea835f5100b7945da7b89d461883e3add01
Author: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
AuthorDate: Tue Aug 16 11:22:18 2022 +0200
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Tue Aug 16 11:22:18 2022 +0200

drivers/char: reset XHCI ports when initializing dbc

Reset ports, to force host system to re-enumerate devices. Otheriwse it
will require the cable to be re-plugged, or will wait in the
"configuring" state indefinitely.

Trick and code copied from Linux:
drivers/usb/early/xhci-dbc.c:xdbc_start()->xdbc_reset_debug_port()

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
xen/drivers/char/xhci-dbc.c | 75 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)

diff --git a/xen/drivers/char/xhci-dbc.c b/xen/drivers/char/xhci-dbc.c
index a16c81b9e7..8c9dfa6cfc 100644
--- a/xen/drivers/char/xhci-dbc.c
+++ b/xen/drivers/char/xhci-dbc.c
@@ -66,6 +66,10 @@
((1UL << DBC_PSC_CSC) | (1UL << DBC_PSC_PRC) | (1UL << DBC_PSC_PLC) | \
(1UL << DBC_PSC_CEC))

+#define XHC_EXT_PORT_MAJOR(x) (((x) >> 24) & 0xff)
+#define PORT_RESET (1 << 4)
+#define PORT_CONNECT (1 << 0)
+
#define dbc_debug(...) printk("dbc debug: " __VA_ARGS__)
#define dbc_alert(...) printk("dbc alert: " __VA_ARGS__)
#define dbc_error(...) printk("dbc error: " __VA_ARGS__)
@@ -666,6 +670,73 @@ static void dbc_init_strings(struct dbc *dbc, uint32_t *info)
&dbc->dbc_ctx->serial_size);
}

+static void dbc_do_reset_debug_port(struct dbc *dbc,
+ unsigned int id, unsigned int count)
+{
+ uint32_t __iomem *ops_reg;
+ uint32_t __iomem *portsc;
+ uint32_t val, cap_length;
+ unsigned int i;
+
+ cap_length = readl(dbc->xhc_mmio) & 0xff;
+ ops_reg = dbc->xhc_mmio + cap_length;
+
+ id--;
+ for ( i = id; i < (id + count); i++ )
+ {
+ portsc = ops_reg + 0x100 + i * 0x4;
+ val = readl(portsc);
+ if ( !(val & PORT_CONNECT) )
+ writel(val | PORT_RESET, portsc);
+ }
+}
+
+static void dbc_reset_debug_port(struct dbc *dbc)
+{
+ uint32_t val, port_offset, port_count;
+ uint32_t __iomem *xcap;
+ uint32_t xcap_val;
+ uint32_t next;
+ uint32_t id;
+ uint8_t __iomem *mmio = (uint8_t *)dbc->xhc_mmio;
+ uint32_t __iomem *hccp1 = (uint32_t *)(mmio + 0x10);
+ const uint32_t PROTOCOL_ID = 0x2;
+ int ttl = 48;
+
+ xcap = (uint32_t *)dbc->xhc_mmio;
+ /*
+ * This is initially an offset to the first capability. All the offsets
+ * (both in HCCP1 and then next capability pointer are dword-based.
+ */
+ next = (readl(hccp1) & 0xFFFF0000) >> 16;
+
+ /*
+ * Look for "supported protocol" capability, major revision 3.
+ * There may be multiple of them.
+ */
+ while ( next && ttl-- )
+ {
+ xcap += next;
+ xcap_val = readl(xcap);
+ id = xcap_val & 0xFF;
+ next = (xcap_val & 0xFF00) >> 8;
+
+ if ( id != PROTOCOL_ID )
+ continue;
+
+ if ( XHC_EXT_PORT_MAJOR(xcap_val) != 0x3 )
+ continue;
+
+ /* extract ports offset and count from the capability structure */
+ val = readl(xcap + 2);
+ port_offset = val & 0xff;
+ port_count = (val >> 8) & 0xff;
+
+ /* and reset them all */
+ dbc_do_reset_debug_port(dbc, port_offset, port_count);
+ }
+}
+
static void dbc_enable_dbc(struct dbc *dbc)
{
struct dbc_reg *reg = dbc->dbc_reg;
@@ -677,6 +748,10 @@ static void dbc_enable_dbc(struct dbc *dbc)
while ( (readl(&reg->ctrl) & (1U << DBC_CTRL_DCE)) == 0 )
cpu_relax();

+ /* reset ports on initial open, to force re-enumerating by the host */
+ if ( !dbc->open )
+ dbc_reset_debug_port(dbc);
+
wmb();
writel(readl(&reg->portsc) | (1U << DBC_PSC_PED), &reg->portsc);
wmb();
--
generated by git-patchbot for /home/xen/git/xen.git#staging